Medical devices involving fluid flow typically include check valves to ensure proper functioning. A hemodialysis device can function in place of a kidney by filtering waste, salt, and fluid from a patient's blood when the patient's kidneys do not function properly. A fluid flow path in a hemodialysis device may include one or more check valves to ensure proper fluid flow through the device. However, the check valves are subjected to high temperatures of up to 90° C., and a high pressure pulsating fluid flow of approximately 12,000,000 cycles per year at approximately 15 psi every 1.1 seconds. Additionally, the fluid contents may be corrosive, including salt water, bleach, acetic acid, paracetic acid, and citric acid.
Known check valves are unable to withstand this harsh environment for long periods of time, requiring frequent replacement. The hemodialysis device must then be taken out of service for maintenance. When the check valve is replaced, a user must be able to quickly and correctly align it properly in the fluid flow path. However, symmetrical check valves make it difficult for users to determine correct alignment, and markings that may be on a check valve are difficult to see in working conditions. If installed improperly, the device may require additional maintenance downtime for corrections.
Additionally, corrosive fluid flowing through the check valve can cause components to corrode and prematurely fail. For example, a spring and poppet assembly in the check valve maintains the seal in the check valve. Over time valve assembly components may corrode, affecting the sealing capability of the check valve. The fluid flow may also cause particulate build-up at the valve seat, which over time may also affect the sealing capability of the check valve. Valve bodies may also comprise multiple pieces which introduce multiple points where leakage can occur should components of the valve fail. When the check valve can no longer seal and prevent fluid backflow and/or leakage occurs, replacement is necessary.
It is with respect to these and other considerations that the present improvements may be useful.